基于绕线转子异步电机的风电轮毂无刷供电系统

目前风电机组轮毂供电普遍采用集电环加电刷的滑动接触方式,存在可靠性差、维护成本高等问题。为解决该问题,提出一种无刷供电系统,采用三相绕线转子异步电机来替代机舱辅助变压器和集电环、电刷,电机定子绕组联接机舱主变压器二次侧,转子则随轮毂旋转并为轮毂中的变桨系统供电。通过解析和仿真方法分析了该电机的电压调整率与其参数的关系。在不改变电机基本尺寸的条件下,通过在定子侧串接补偿电容,有效地减低了电压调整率,在短时过载运行时效果尤其明显;同时,转子采用双三相绕组,可减小联接不控整流电路时的网侧谐波。通过实验证明了所提系统的有效性。

A Wound-rotor Induction Machine Based Brushless Power Supply System for the Hub of Wind Turbine

A sliding contact scheme with collector rings and brushes is universally utilized for powering the hub of a wind turbine at present, leading to some problems such as poor reliability and high maintenance cost. In order to solve such problems, this paper proposesd a brushless power supply system with a three-phase wound-rotor induction machine to replace the auxiliary transformer, the collector rings and the brushes. The stator windings of the machine were connected to the distribution transformer in the nacelle, and the rotor windings power the pitch system in the hub while rotating with it. The relationship between the voltage regulation of the machine and its parameters was analyzed by analytical and simulation methods. Under the condition of not modifying the machine basic size, the voltage regulation was effectively reduced by adding capacitors in series with the stator windings, especially in short-time overload operation. Meanwhile, the double three-phase rotor windings were used to reduce the harmonics to the grid side resulting from the uncontrolled rectifier circuit. The effectiveness of the proposed system was proved by experiments.